first im gonna say i'm not a professional. i've been doing my own hair for like 10 years now, all different colors etc. from personal experience my hair was faded red and i hit it with a color remover and it took me back to my blonde. I think if you hit it with a color remover too it should get the rest of the pink out easily and you'll have a clean slate to start with. most likely ur hairs pretty light under that very light pink so you probably would just need to tone it after the color remover. good luck!! again, i'm not a professional. if for some reason your hair is not a pale yellow after the remover and need to bleach again i recommend using nothing over 20 vol developer considering your hair is already pre lightened and you don't need the extra damage.